The invention relates to nanoparticles of lithium metal oxides, in particular, in which the non-lithium metal includes, for example, cobalt, nickel, titanium, or combinations thereof with one or more additional metals. The invention further relates to electrodes and batteries formed from the lithium metal oxide nanoparticles.
Advances in a variety of fields have created a demand for many types of new materials. In particular, a variety of chemical powders can be used in many different processing contexts, such as the production of batteries. The microminiaturization of electronic components has created widespread growth in the use of portable electronic devices such as cellular phones, pagers, video cameras, facsimile machines, portable stereophonic equipment, personal organizers and personal computers. The growing use of portable electronic equipment has created ever increasing demand for improved power sources for these devices. Relevant batteries include primary batteries, i.e., batteries designed for use through a single charging cycle, and secondary batteries, i.e., batteries designed to be rechargeable. Some batteries designed essentially as primary batteries may be rechargeable to some extent.
Batteries based on lithium have been the subject of considerable development effort and are being sold commercially. Lithium-based batteries generally use electrolytes containing lithium ions. The negative electrodes for these batteries can include lithium metal or alloy (lithium batteries), or compositions that intercalate lithium (lithium ion batteries). Preferred electroactive materials for incorporation into the positive electrodes are compositions that intercalate lithium. The compositions that intercalate lithium, for use in the positive electrodes, generally are chalcogenides such as metal oxides that can incorporate the lithium ions into their lattice.
A variety of lithium metal oxides, such as lithium cobalt oxides, lithium nickel oxides and derivatives thereof have been noted as promising materials for use in positive electrodes for lithium-based batteries. Similarly, lithium titanium oxides have been noted as promising materials for use in negative electrodes for lithium-based batteries. These lithium metal oxides are useful for the production of lithium-based secondary batteries. Because of the interest in lithium metal oxides, several approaches have been developed for producing lithium metal oxide powders.
In a first aspect, the invention pertains to a collection of particles comprising lithium cobalt oxide or derivatives thereof, the collection of particles having an average diameter less than about 100 nm.
In a further aspect, the invention pertains to a collection of particles comprising lithium nickel oxide or derivatives thereof, the collection of particles having an average diameter less than about 100 nm.
In another aspect, the invention pertains to a collection of particles comprising lithium titanium oxide or derivatives thereof, wherein the collection of particles have an average diameter less than about 100 nm.
Moreover, the invention pertains to batteries formed from nanoparticles of lithium cobalt oxide, lithium nickel oxide, lithium titanium oxide or derivatives thereof.
Furthermore, the invention pertains to a battery comprising an anode and a cathode, the anode comprising lithium titanium oxide and the cathode comprising lithium manganese cobalt oxide.
In a further aspect, the invention pertains to a method of producing lithium metal oxide particles wherein the lithium metal oxide comprises a metal-1 and a metal-2, the method comprising heating precursors particles in an oxidizing atmosphere. The precursor particles being formed by reacting a precursor aerosol, the aerosol comprising precursor compounds of lithium, metal-1 and metal-2. The relative amounts of lithium, metal-1 and metal-2 are selected to yield a desired stoichiometry of the resulting mixed metal oxides.